Chances are Chad Clifton is taking fewer snaps than any healthy starter in any training camp around the NFL.

The Green Bay Packers left tackle has arthritic knees and at age 35 is the NFL’s oldest starter at that demanding position and the third-oldest starting offensive lineman overall, behind only Kansas City’s Casey Wiegmann (37) and Indianapolis’ Jeff Saturday (35), both of whom play center.

The Packers have spent years learning to manage Clifton’s chronically sore knees and since the early 2000s have given him regular days off in training camp and during the regular season to make sure he’s feeling OK on Sundays.

But in this year’s camp they’ve cut back on his playing time even further, often playing him only a snap or two per team period. There also are practices, even with only one practice a day, when he doesn’t do any 11-on-11 work and takes part only in individual drills.

So far, at least, it seems to be working. Clifton says his knees are holding up and he’s feeling only the typical soreness that all players do in camp. And his performance in two series in the preseason opener didn’t suffer from rust.

“He looked good the other night,” said Joe Philbin, the Packers’ offensive coordinator. “He’s getting some good work in individual (drills). I’m hopeful. A player at that stage in his career, you have to have a little faith that he knows how much he needs and what he doesn’t need. I think he looks good.”

Clifton was one of the surprises of the Packers’ Super Bowl run last year, at least considering how he looked in Week 2. In that home game against Buffalo, the Packers pulled him in the first half because of performance – his right knee was so inflamed and irritated that he couldn’t play at a starter’s level.

There was reason to wonder whether it was the beginning of the end of a distinguished NFL career. Clifton’s knees had been chronically sore since his return from the devastating separated pelvis he sustained on a Warren Sapp blind-side block in 2002, and maybe he was hitting an age when the swelling and irritation were too much to overcome.

“That was definitely the low point of last year,” Clifton said. “I was like, ‘Oh man, something has to be done to calm this knee down or it’s done.’ Fortunately we were able to do that.”

The Packers took two steps to help him: They scaled back his already abridged practice schedule and had him undergo an injected treatment called Euflexxa to lubricate his arthritic right knee. Starting after the Bills game, Clifton had one injection in his knee per week for three weeks with a form of hyaluronic acid that’s similar to the natural substances that lubricate a healthy knee.

“I haven’t had an issue since,” Clifton said.

Clifton also puts in long hours taking care of his knee, and with his daily pre- and post-practice treatment and rehabilitation regimen probably spends more time than any other player in the Packers’ training room, which is an honor no player wants. But it helps him to play at age 35 despite multiple arthroscopic surgeries to both knees, and the demands of a position where he’s blocking the NFL’s premier outside pass rushers, usually one-on-one.

“He’s been diligent,” Philbin said. “Good, bad or indifferent, he’s spent some time in that (training) room over there taking care of his body. I don’t think he’s a hard liver (off the field), his wife’s got him reined in pretty good. And he’s blessed obviously, some pretty good natural ability.”

Perhaps most surprising was how well Clifton finished last season. Longtime NFL scouts will tell you that older, declining players often perform well enough through the early and middle portions of a season but then slip late in the year. Clifton, though, played his best over the last six games — two to end the regular season, and then four games in the playoffs.

Each of those weeks, he faced a quality defensive end or outside linebacker: Chicago’s Julius Peppers twice, the New York Giants’ Osi Umenyiora, Philadelphia’s Trent Cole, Atlanta’s John Abraham and Pittsburgh’s James Harrison.

“Fortunately we were able to calm (the knee pain) down and I played some good football,” Clifton said.

Clifton also continues to play at a starter’s level because of the athletic ability that most NFL teams underestimated when he came out of college in 2000. He’d played left tackle his final three years at Tennessee but was moved to guard for the Senior Bowl, and he said most teams told him and his agent that he probably was a guard, or maybe a right tackle, in the NFL. But former Packers General Manager Ron Wolf drafted him in the second round as a left tackle, and from his first practice with the Packers he proved to be more than athletic enough to play there.

Clifton never has been a good run blocker, and that skill has suffered more as he’s aged and lost flexibility. But the NFL is a passing league and teams place a premium on protecting their quarterback’s blind side. In that way, Clifton is something of a marvel at his age.

“Just look how explosive he is out of his stance,” said James Campen, the Packers’ offensive line coach. “And his posture is good, the ‘Z’ in his knees and his elbows, he’s very compact. Doesn’t give a lot of surface for the defender to rush him.”

Especially considering Clifton’s age and knee history, there’s no knowing whether he will make it through another NFL season. Since ’03 he’s actually missed only six starts, but with each passing season the chances increase that his next knee flare-up will be the end.

However, he made it through last season after that ominous Week 2, and he’s hoping to fulfill his contract, which this year will pay him up to $6.25 million in salary and bonuses and runs through next year, with a 2012 salary of $5.25 million plus another possible $500,000 in roster and workout bonuses. But he’ll have to be performing at a relatively high level to return at a starting salary in ’12, because the Packers selected a tackle in the first round each of the last two drafts, which means his likely successor already is on the roster.

“I want to be able to finish out these two years and finish up in Green Bay,” Clifton said. “We’ll see how that plays out, how the knee holds up, which I think it can.”